Design and manufacturing process for Lithium-ion battery

Author:Source:Datetime: 2016-10-06 14:43:05

In the battery design process, the choice of materials is the most important factor. Different performance characteristics of different materials, the battery performance is also a gap. Positive and negative materials match the cycle performance, the battery life cycle will grow. In the ingredients, we should pay attention to positive and negative materials added.

In general, the design of the assembly process generally requires a negative relative to the cathode capacity of some excess, if not excessive, the negative charge during the precipitation of lithium, the formation of lithium dendrite and thus affect the safety, so it is careful process for produce that batteries, such as LiFePo4 battery pack. Negative too much positive relative to the cathode, the cathode may be excessive lithium, resulting in structural collapse.

Electrolyte in the battery reversible capacity is also very important factor. The process of electrode material deintercalation and intercalation of lithium ions is always the process of interaction with the electrolyte, which has an important influence on the interface condition and internal structure of electrode materials. In the process of interaction with the anode material will be loss of electrolyte, while the formation of the battery into the SEI film and pre-charging, it will consume part of the electrolyte, so the type of electrolyte and injection volume also affects battery life.

Lithium-ion battery manufacturing process include: positive and negative ingredients, coating, production, winding, shell, liquid injection, sealing, chemical and so on. In the battery production process, the process for each step are very strict requirements. Any process is not controlled are likely to affect the battery cycle performance.

In the positive and negative ingredients in the process, should pay attention to the amount of binder, stirring speed, slurry concentration, temperature and humidity, and to ensure that the material can be dispersed evenly.

In the process of coating, under the premise of ensuring the high specific energy of the battery, it is reasonable to control the amount of positive (negative) pole coating and reduce the thickness of the electrode to reduce the rate of battery decay. After coating the pole pieces but also to further compact with the roller press, the cathode density can increase the appropriate discharge capacity of the battery, reducing internal resistance, reduce polarization losses, extend the battery cycle life. The battery can be used in portable solar power generator.

Winding, rolled into the batteries should be tight, not loose. Diaphragm and positive and negative volume rolled more tightly, the smaller the internal resistance, but the volume is too tight will cause the polar pieces and diaphragm wet difficult, resulting in smaller discharge capacity; roll too loose will make the film in the process of over-expansion , Increasing the internal resistance, reducing the capacity and shorten the cycle life.